Access to in-vehicle electronics is known in the art. Access to in-vehicle electronics currently requires special hardware that is connected directly to the vehicle bus through some physical connection. Traditional built-in in-car navigation systems use vehicle data such as wheel speed and steering angle to extrapolate from a former navigation solution. In the case of a satellite-based positioning system, for instance GPS (Global Positioning System), if there is no GPS signal available, the current navigation solution is approximated by using the vehicle data to extrapolate from the last-received (or former) GPS position. Internal vehicle data increases both precision and coverage of the navigation solution. Diagnostics systems use vehicle data obtained from a vehicle bus to assist an automotive technician in diagnosing and repairing vehicle systems.
There are several inherent problems with the current method of accessing in-vehicle electronic information for the purpose of improving a navigation solution or for the purpose of vehicle diagnostics. One problem is the cost of creating a hardwire connection from the vehicle bus to a navigation system or a handheld computer. For the case of the navigation system, this cost is due in part to the fact that most navigation systems are currently installed in the aftermarket. For the case of vehicle diagnostics, this cost is due in part to the fact that most diagnostic systems are only installed temporarily. Therefore, each installation is essentially a custom job, requiring a relatively large amount of time from an experienced automobile technician. Additionally, it may be difficult to find a connection to the vehicle bus if the automobile technician is not entirely familiar with the layout of the car, adding to the total time expended.
Another problem with the current method of attachment to the in-vehicle electronics is the flexibility provided by the vehicle bus connection. With the connector attached to the vehicle, the operator is often forced to use a specific navigation system, or a specific diagnostics computer, which the connector is designed to accommodate. A vehicle operator might want to use the navigation system (or vehicle diagnostics computer) outside the vehicle, and therefore the connection must be disconnectable. Additionally, the vehicle operator might want to upgrade or change the navigation system (or vehicle diagnostics computer) for the vehicle, possibly requiring a new connection to the vehicle bus, or a specialized adapter for the old bus connector. The uncertainty and non-uniformity in the connections to the vehicle bus have a substantial effect on the cost of both in-vehicle navigation systems and vehicle diagnostics systems, and have therefore had a profoundly negative effect on the use of in-vehicle navigation systems and vehicle diagnostics systems.
U.S. patent application Ser. No. 09/687,181 describes a system for providing short-range wireless access to data on vehicle buses and data in the memory of electronic control units (ECUs) via a wireless link. This application discusses interfacing a CAN (Controller Area Network) protocol on the vehicle bus communicating with a gateway node and Bluetooth hardware set.
Mobile navigation systems, as described in Gabler, U.: “Temporary engagement”, Traffic Technology International, pp. 100-101, can consist of a handheld computer, a cell phone, and/or a GPS receiver. These systems, referred to as component-based mobile navigation systems (CBMNS), can be used both inside and outside a vehicle, in contrast to an in-vehicle navigation system, which is used exclusively within the vehicle.
While in-car navigation systems are an integral part of the vehicle, the component-based mobile navigation system uses less expensive components that may also be useful for functions other than navigation.